Base for supporting an exhibition stall upright post



FIG. 1 is a bottom plan view of the base showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof; and,

FIG. 4 is a top perspective view thereof. 

The ornamental design for a base for supporting an exhibition stall upright post, substantially as shown and described. 